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Strontium Program: Quarterly Summary Report, January 1, 1960

Description: From Abstract: "This report is one of the a sequence of quarterly reports, each designed to up-date its predecessor beginning with HASL-42, "Environmental Contamination from Weapon Tests." Herein are presented data accrued since HASL-69. Plutonium-239 and cesium-137 levels in human tissue and other biological materials are also presented."
Date: January 1, 1960
Creator: Hardy, Edward P., Jr. & Klein, Stanley
Partner: UNT Libraries Government Documents Department

Use of an Eductor to Reliably Dilute a Plutonium Solution

Description: Savannah River Site (SRS) in South Carolina is dissolving Pu239 scrap, which is a legacy from the production of nuclear weapons materials, and will later convert it into oxide form to stabilize it. An eductor has been used to both dilute and transfer a plutonium containing solution between tanks. Eductors have the advantages of simplicity and no moving parts. Reliable control of dilution is important because the geometry of the receiving tank could potentially allow a nuclear criticality. Dilution factor was to have been controlled by the appropriate choice of flow restrictor in the line between the plutonium solution tank and the eductor. However, dilution factors measured for liquid transfers with different flow restrictors showed unexpected trends, causing concern that the process was not well understood. As a result, the performance of the eductor and associated piping were analyzed using a mathematical model. The one dimensional, two phase model accounted for eductor performance and for air and vapor coming out of solution at low pressures. The unexpected trends were shown to be the result of variations in viscosities and densities of both the plutonium solution and the nitric acid solution used as both the motive fluid and diluent. The model agreed well with existing data and was then used to make pre-test predictions of flows for four solution transfers with good agreement. This provided confidence that the eductor system was a reliable method for obtaining specified dilution factors. Based on model results, recommendations were made and implemented for the operation of the eductor transfer system. One unexpected result of the analysis was the observation that slow corrosion inside the eductor is increasing the dilution factor, which is a conservative trend.
Date: March 23, 1999
Creator: Steimke, J.L.
Partner: UNT Libraries Government Documents Department

Plutonium 239 Equivalency Calculations

Description: This document provides the basis for converting actual weapons grade plutonium mass to a plutonium equivalency (PuE) mass of Plutonium 239. The conversion can be accomplished by performing calculations utilizing either: (1) Isotopic conversions factors (CF{sub isotope}), or (2) 30-year-old weapons grade conversion factor (CF{sub 30 yr}) Both of these methods are provided in this document. Material mass and isotopic data are needed to calculate PuE using the isotopic conversion factors, which will provide the actual PuE value at the time of calculation. PuE is the summation of the isotopic masses times their associated isotopic conversion factors for plutonium 239. Isotopic conversion factors are calculated by a normalized equation, relative to Plutonium 239, of specific activity (SA) and cumulated dose inhalation affects based on 50-yr committed effective dose equivalent (CEDE). The isotopic conversion factors for converting weapons grade plutonium to PuE are provided in Table-1. The unit for specific activity (SA) is curies per gram (Ci/g) and the isotopic SA values come from reference [1]. The cumulated dose inhalation effect values in units of rem/Ci are based on 50-yr committed effective dose equivalent (CEDE). A person irradiated by gamma radiation outside the body will receive a dose only during the period of irradiation. However, following an intake by inhalation, some radionuclides persist in the body and irradiate the various tissues for many years. There are three groups CEDE data representing lengths of time of 0.5 (D), 50 (W) and 500 (Y) days, which are in reference [2]. The CEDE values in the (W) group demonstrates the highest dose equivalent value; therefore they are used for the calculation.
Date: May 31, 2011
Creator: Wen, J
Partner: UNT Libraries Government Documents Department

Research in Radiobiology. Annual Report of Work in Progress on the Chronic Toxicity Program

Description: Separate abstracts were prepared on 8 sections of this report. Data are also included on the status of dogs at various time intervals following the injection of various doses of Ra/sup 226/, Pu/sup 239/, Ra/sup 228/, Th/sup 228, and Sr/sup 90/. (C. H.)
Date: March 31, 1962
Creator: Dougherty, T. F.
Partner: UNT Libraries Government Documents Department

Preparation of Pu{sup 239} sources

Description: The Separations Technology Laboratory has prepared four sources to be used for calibrating a waste assay system (Passive/Active Neutron Assay) in Building 724-8G (Burial Ground). The four sources contain 0.5, 0.1, 0.05, and 0.01 grams Pu{sup 239}, respectively. The sources were prepared using aliquots from a single solution provided by the Quality Control (QC) group of Laboratories Department. The solution contained weapons-grade plutonium dissolved in nitric acid. Final solution acidity was 3M. Coulometry had been used to obtain a total plutonium content per unit volume. The weight percent of the plutonium isotopes present was obtained via mass spectrometry.
Date: August 5, 1988
Creator: Holcomb, H. P.
Partner: UNT Libraries Government Documents Department

Tank 241-AN-104, cores 163 and 164 analytical results for thefinal report

Description: This document is the analytical laboratory report for tank 241-AN-104 push mode core segments collected between August 8, 1996 and September 12, 1996. The segments were subsampled and analyzed in accordance with the Tank 241-AAr-1 04 Push Mode Core Sampling and Analysis Plan (TSAP) (Winkleman, 1996), the Safety Screening Data Quality Objective (DQO) (Dukelow, et at., 1995) and the Flammable Gas Data Quality Objective (DQO) (Benar, 1995). The analytical results are included in a data summary table. None of the samples submitted for Differential Scanning Calorimetry (DSC), Total Alpha Activity (AT), Total Organic Carbon (TOC) and Plutonium analyses (239,240 Pu) exceeded notification limits as stated in the TSAP. The statistical results of the 95% confidence interval on the mean calculations are provided by the Tank Waste Remediation Systems Technical Basis Group in accordance with the Memorandum of Understanding (Schreiber, 1997) and not considered in this report.
Date: June 5, 1997
Creator: Steen, F.H.
Partner: UNT Libraries Government Documents Department

Comparison of attenuation correction methods for TGS and SGS: Do we really need selenium-75?

Description: We compared attenuation-coefficient mapping techniques for use in tomographic gamma scanner (TGS) image reconstructions to determine whether there is a significant improvement when using fully coupled methods. For the constrained least-squares image reconstruction method tested here, we found no significant improvement. We also compared the effectiveness of different transmission source combinations for 129- and 414-keV {sup 239}Pu TGS assays. We concluded that the best source combination for TGS assays of {sup 239}Pu and other isotopes is a mixture of {sup 133}Ba, {sup 54}Mn, and {sup 60}Co. Three other source combinations were found to be at least as effective as {sup 75}Se.
Date: September 1, 1996
Creator: Estep, R.J.; Prettyman, T.H. & Sheppard, G.A.
Partner: UNT Libraries Government Documents Department

Plutonium in human urine: Normal levels in the US public. 1991 Annual report, Volume 2

Description: A neutron induced fission track method was successfully developed for assaying {sup 239}Pu in human urine with a detection limit below 20 aCi/sample. The technique involves the co-precipitation of {sup 239}Pu with rhodizonic acid, separation of {sup 239}Pu from potentially interfering natural uranium and other inorganic materials by ion-exchange techniques, collection of the sample onto lexan detectors, irradiation of sample in MIT reactor at a fluence of 1.1 x 10{sup 17} n/cm{sup 2}, etching of the lexan slide and counting the track either manually or by some automated counting system.
Date: March 1, 1997
Creator: Wrenn, M.E.; Singh, N.P. & Xue, Ying-Hua
Partner: UNT Libraries Government Documents Department

Migration of Sr-20, Cs-137, and Pu-239/240 in Canyon below Los Alamos outfall

Description: Technical Area-21 (TA-21) of Los Alamos National Laboratory (LANL) is on a mesa bordered by two canyons DP Canyon and Los Alamos (LA) Canyon. DP Canyon is a small semiarid watershed with a well defined channel system where the stream flow is ephemeral. TA-21 has had a complex history of waste disposal as research to determine the chemical and metallurgical properties of nuclear materials occurred here from 1945-1978. Due to these operations, the TA-21 mesa top and bordering canyons have been monitored and characterized by the LANL Environmental Restoration Program. Results identify radionuclide values at outfall. 21-011 (k) which exceed Screening Action Levels, and points along DP Canyon which exceed regional background levels. The radiocontaminants considered in this study are strontium-90, cesium-137, and plutonium-239. This research examines sediment transport and speciation of radionuclide contaminant migration from a source term named SWMU 21-011 (k) down DP Canyon. Three dimensional surface plots of data from 1977-1994 are used to portray the transport and redistribution of radioactive contaminants in an alluvial stream channel. An overall decrease in contamination concentration since 1983 has been observed which could be due to more stringent laboratory controls and also to the removal of main plutonium processing laboratories to another site.
Date: April 1, 1996
Creator: Murphy, J.M.; Mason, C.F.V.; Boak, J.M. & Longmire, P.A.
Partner: UNT Libraries Government Documents Department

The 239 Pu(n,2n)238Pu cross section: preliminary calculations

Description: The primary motivation for the present work is to provide theoretical values for the ratio of the partial <sup>239</sup>Pu(n,2nx{gamma})<sup>238</sup>Pu to total <sup>239</sup> Pu(n,2n)<sup>238</sup>Pu cross section for several discrete gamma transitions. Results and conclusions of preliminary calculations from threshold to 20 MeV are presented. Calculations are based on theoretical models with parameters obtained from the literature or from our ad hoc systematics. Optical model cross sections and transmission coefficients were determined using the coupled-channels method. The calculations included a preequilibrium component followed by multiple particle and gamma-ray emissions. Fission competition was included at all stages of de-excitation. Suggestions for further verifications and possible improvements are provided.
Date: March 12, 1999
Creator: Chen, H.; Reffo, G.; Ross, M. A. & White, R. M.
Partner: UNT Libraries Government Documents Department

Crystalline ceramics: Waste forms for the disposal of weapons plutonium

Description: At present, there are three seriously considered options for the disposition of excess weapons plutonium: (i) incorporation, partial burn-up and direct disposal of MOX-fuel; (ii) vitrification with defense waste and disposal as glass ``logs``; (iii) deep borehole disposal (National Academy of Sciences Report, 1994). The first two options provide a safeguard due to the high activity of fission products in the irradiated fuel and the defense waste. The latter option has only been examined in a preliminary manner, and the exact form of the plutonium has not been identified. In this paper, we review the potential for the immobilization of plutonium in highly durable crystalline ceramics apatite, pyrochlore, monazite and zircon. Based on available data, we propose zircon as the preferred crystalline ceramic for the permanent disposition of excess weapons plutonium.
Date: May 1, 1995
Creator: Ewing, R.C.; Lutze, W. & Weber, W.J.
Partner: UNT Libraries Government Documents Department

Area G Perimeter Surface-Soil and Single-Stage Water Sampling: Environmental Surveillance for Fiscal Years 1996 and 1997, Group ESH-19

Description: Area Gin Technical Area 54, has been the principal facility at Los Alamos National Laboratory for the storage and disposal of low-level, solid mixed, and transuranic radioactive waste since 1957. Soil samples were analyzed for tritium, isotopic plutonium, americium-241, and cesium-137. Thirteen metals-silver, arsenic, barium, beryllium, cadmium, chromium, mercury, nickel, lead, antimony, selenium, thallium and zinc-were analyzed on filtered-sediment fractions of the single-stage samples using standard analytical chemistry techniques. During the two years of sampling discussed in this report elevated levels of tritium (as high as 716,000 pCi/L) in soil were found for sampling sites adjacent to the tritium burial shafts located on the south- central perimeter of Area G. Additionally, tritium concentrations in soil as high as 38,300 pCi/L were detected adjacent to the TRU pads in the northeast comer of Area G. Plutonium-238 activities in FY96 soils ranged from 0.001-2.866 pCi/g, with an average concentration of 0.336& 0.734 pCdg. Pu-238 activities in FY97 soils ranged from 0.002-4.890 pCi/g, with an average concentration of 0.437 & 0.928 pCdg. Pu-239 activities in FY96 soils ranged from 0.009 to 1.62 pCdg, with an average of 0.177- 0.297 pCdg. Pu-239 activities in FY97 soils ranged from 0.005 to 1.71 pCi/g, with an average of 0.290- 0.415 pCi/g. The locations of elevated plutonium readings were consistent with the history of plutonium disposal at Area G. The two areas of elevated Am-241 activity reflected the elevated activities found for plutonium, the average values for Am-241 on soils were 0.6-2.07 pCi/g, and 0.10-0.14 pCi/g respectively for samples collected in FY96 and FY97. CS-137 activities in soils had average values of 0.33 pCi/g, and 0.28 pCi/g respectively for samples collected in FY96 and 97. There was no perimeter area where soil concentrations of CS-137 were significantly elevated.
Date: October 1, 1998
Creator: Childs, Marquis & Conrad, Ron
Partner: UNT Libraries Government Documents Department

Nuclear waste management and criticality safety

Description: Since 1945 waste streams containing radioactive isotopes have been discharged to underground storage tanks on the Hanford Site in Washington State. At least 49 different waste streams containing low concentrations of {sup 235}U and {sup 239}Pu have been transferred to tank farm facilities. Optimizing tank space, combined with the variability of operations, results in a complex waste matrix that is difficult to characterize. Characterizing tank waste is difficult because of its relative inaccessibility inside the storage tanks and because of the large degree of uncertainty in the composition and distribution of components. Nuclear criticality safety controls are based on precise configurations that are conservative when used to represent the waste environment. However, the safety philosophy governing waste storage requires that the waste be controlled and monitored, and the margin of safety be quantified.
Date: July 1, 1995
Creator: Vail, T.S.
Partner: UNT Libraries Government Documents Department

FEASIBILITY OF Pu$sup 239$-U$sup 235$-FUELED CORES TO PREDICT Pu$sup 239$- FUELED CORE DIMENSIONS

Description: Use of Pu/sup 239/ -- U/sup 235/-fueled fast critical assemblies to estimate properties of Pu/sup 239/-fueled assemblies is of interest because of safety considerations and limited plutonium availability. Bare and reflected homogeneous cores and reflected two-region cores are considered. The fuel, 5% by volume, is assumed to be Pu/sup 239/ and U/sup 235/ of various fuel composition ratios for the homogeneous cores. For the tworegion cores the 5% fuel volume is Pu/sup 235/ in the central region and U/sup 235/ in the outer core region. Core diluents, simulating fertile, structural, and coolant materials, are assumed identical in all cases. it is estimated that construction of the reflected two- region core with ratio of central core region volume to total core volume of 0.1 will theoretically decrease the calculated error in prediction of the critical size of a corresponding solely Pu/sup 239/-fueled assembly by a factor of about 10 to 20. (auth)
Date: June 1, 1962
Creator: Meneghetti, D. & Ishikawa, H.
Partner: UNT Libraries Government Documents Department